1. Field of the Invention
The present invention relates to a mobile communication, and more particularly, to a method of setting up a PS call in a mobile communication system. Although the present invention is suitable for a wide scope of applications, it is particularly suitable for setting up a PS (packet switched) call for a packet switched data service in a mobile communication system.
2. Discussion of the Related Art
Generally, the remarkable development of an information communication field brings about rapid changes of information and communication environments. And, a mobile communication terminal is globally used and regarded as a living necessary in the modern society. To cope with the user's demand according to the global use of the mobile communication terminal, an Internet access function is added to the mobile communication terminal having a general voice communication function.
In a 2nd generation or higher mobile communication network that supports a packet switched data service, it is possible for a mobile communication terminal to access the Internet via the mobile communication network.
A process that a mobile communication terminal accesses the Internet via a mobile communication network according to a related art is explained in brief as follows.
First of all, a mobile communication terminal makes a request for a PS call connection to a packet switched data service network.
If the PS call connection request is accepted by the packet switched data service network, the PS call connection is established between the mobile communication terminal and the packet switched data service network. After the PS call connection is established, the mobile communication terminal then receives an IP address of a DNS server responsible for the packet switched data service network from the packet switched data service network.
However, if an incorrect IP address is transmitted to the mobile communication terminal due to an error of a noise on a radio transmission or if the DNS server is operating erroneously, the mobile communication terminal may be unable to access the DNS server despite the established PS call.
Thus, despite the established PS call for an Internet access, the mobile communication terminal is unable to access the DNS server and the Internet access is not achieved. Hence, the established PS call becomes a waste of resource.